Currently, the closing mechanism of watertight doors, which are often used in marine vessels, have a number of latches arranged around the door and these latches are each connected to a rod system. An operating member, such as a lever or a turning wheel, is also connected to this rod system, in order to operate each latch simultaneously by operating the operating member.
In order to properly seal the prior art watertight doors, a large amount of force is required to compress one or more gaskets to obtain a watertight seal. The typical hinged watertight door found on Navy vessels utilizes a “compression gasket” for sealing. This arrangement requires about 30 lbs of compression force per linear inch of gasket. For a 30″×66″ door, this translates to 5760 lbs of force that has to be generated by the latches. This large compression force often necessitates a complicated latch mechanism to produce the mechanical advantage required for manual operation. The high loading, due to the large compression force required, results in worn parts and frequent maintenance, particularly for high traffic doors. The high loading also forces the mechanism to be bulky which adds significantly to the overall weight of the door. The typical gasket for the prior art door has a very small tolerance for variations in flatness. This requires the door panel and frame to be stiff and heavy to limit deformation under load that would compromise the seal. It also makes prior art doors very sensitive to welding distortion that may occur during the installation process. Additionally, the prior art doors usually require a raised threshold to function. Also, the mechanism on most prior art doors is external and exposed. This makes the prior art door aesthetically obtrusive and prone to tampering and external damage.
The typical prior art door has been described by the Navy as “heavy, unreliable and very expensive to maintain over the life cycle of the ship”.
Thus, there is a need for a watertight door and closing mechanism for a watertight door that overcome the above listed and other disadvantages of prior art watertight doors.